Unsteady-state retention of sulfur dioxide in a fluidized bed with continual feeding of lime and limestone

Hartman, Miloslav; Svoboda, Karel; Trnka, O.

doi:10.1021/ie00056a027

Cited by 10 publications

(11 citation statements)

References 8 publications

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“…Pollutants are removed by the entrained sorbent particles in the duct and by passing through a sorbent bed in the particulate collector. Other mode of the gas-solid contact can be attained in a bubbling or circulating fluidized bed (for example, Hartman et al, 1983; Yates, 1983; Hartman et al, 1991). The reactivity of sorbent and efficient contact between gas and solid are among the major factors effecting the separation performance.…”

Section: Introductionmentioning

confidence: 99%

Reactions between calcium oxide and flue gas containing sulfur dioxide at lower temperatures

Hartman¹,

Trnka²

1993

AIChE Journal

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An experimental study has been performed of the reactions occurring when the reacfive particles of calcium oxide are exposed to sulfur dioxide bearing flue gas. Using a differential, fixed-bed reactor, kinetic measurements have been made in the temperature range of I70 and 580°C. A relatively simple correlation based on the amassed data has been proposed. This correlation allows the estimation of the reaction rate as a function of temperature, conversion of thesolids and concentration of sulfur dioxide in the gas phase. The proposed rate law equation makes it possible to predict in a straightforward manner the rate of sorption which would be required to design the performance of a desulfurization unit.

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Section: Introductionmentioning

confidence: 99%

Reactions between calcium oxide and flue gas containing sulfur dioxide at lower temperatures

Hartman¹,

Trnka²

1993

AIChE Journal

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“…Although this groove volume is extremely small, Hartman et al (1991) reported that this design is adequate for continuous and stable filling to the rotor and discharging from the rotor. The air/sorbent mixture was transported to the measurement chamber at a flow rate of 3 L/min through in the inner stainless steel nozzle (ID 4.35 In the measurement chamber, aerosolized sorbent particles expended from the nozzle were sampled using an isokinetic sampling probe with an inner diameter of 4.35 mm.…”

Section: Methodsmentioning

confidence: 99%

“…These sorbent particles have often been used in examinations of the sulfation process of coal combustion power plants (Hartman et al 1991). Our feeding system design is based on the same fundamental operating principle of conventional feeding systems.…”

Section: Design Of the Screw-assisted Rotary Feeding Systemmentioning

confidence: 99%

“…Schneider et al (2007) developed a die-shoe filling system and characterized the flow behavior of pharmaceutical particles in that system. For injecting sorbent particles into a scrubber, several instruments, including rotary-, disk-, and slide-type feeders and fluidized bed solids feeders, have been examined for power plant applications (Francis et al 2009;Hartman et al 1991). Higuchi and Steinhagen (1991), Teague et al (2005), and Veranth et al (2000) developed a dust feeder for use in studies of inhalation.…”

Section: Introductionmentioning

confidence: 99%

“…Although transporting a constant volume of particles with small fluctuation over time and high reproducibility is the most important requirement of a feeding system, each type of feeding system has advantages and disadvantages with respect to reliability, stability and uniformity, ease of construction, and cost (Reist and Taylor 2000). The application of conventional feeding systems to laboratory-scale studies can involve several drawbacks, including high feeding rates, discontinuous feeding characteristics, the absence of short-and/or long-term stability, and the length of time required to stabilize the feeding process (Francis et al 2009;Gundogdu 2004;Hartman et al 1991;Kehlenbeck and Sommer 2003;Pohorely et al 2004). In addition, the use of high carrier gas volume rates for transporting particles by the pressure difference between two pathways is a definite disadvantage in laboratory experiments in which residence time in the reactor according to the flow rate is an important variable (Reist and Taylor 2000).…”

Section: Introductionmentioning

confidence: 99%

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Design and Characterization of an Improved Screw-Assisted Rotary Feeding System for Aerosolization of Ultra-Small Quantities of Particulate Solids

Lee

Jung

Keel

et al. 2010

Aerosol Science and Technology

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Many previous studies have examined solid-state particle discharge systems. However, several drawbacks have been encountered in terms of laboratory-scale particle feeding systems (e.g., high feeding rates, discontinuous feeding characteristics, the absence of long-term stability, and the use of high carrier gas volume rates). In this study, a state-of-the-art screw-assisted rotary feeding system was developed and evaluated in terms of aerosolization characteristics such as particle number concentration, geometric mean diameter, and geometric standard deviation. The various experimental conditions included changes in the rotational speed of the rotor, changes in the number of rotor grooves, and the existence or nonexistence of screw operation. Calcium carbonate (CaCO 3 ) powder was selected as the discharged sorbent particle. To verify the performance of the designed feeding system, we measured number concentrations with and without operation of the screw. Uniformity (i.e., the steadiness of feeding characteristics over time) was analyzed using a condensation particle counter. As the rotational speed and the number of rotor grooves increased, the number concentration and the frequency of discharging sorbent particles increased, whereas the coefficient of variation decreased. However, when the loading time was less than the critical time (∼0.8 s), the number concentration decreased and the coefficient of variation increased again according to the rotational speed. Stability (i.e., the invariability of the size distribution in various rotational speeds sskim@kaist.ac.kr of the rotor for three different rotors) was also analyzed using an aerodynamic particle sizer and a scanning mobility particle sizer. The results of both aerosol measurement and scanning electron microscopy analysis showed that the geometric mean diameter and the geometric standard deviation of aerosolized sorbent particles remained constant under all the experimental conditions. We also determined that the region in which the coefficient of variation was less than 0.1 was the stable operation region for this screw-assisted rotary feeding system.

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A comparison of two-phase and well-mixed models for fluidized-bed polyethylene reactors

McAuley

Talbot

Harris

1994

Chemical Engineering Science

120

105

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Unsteady-state retention of sulfur dioxide in a fluidized bed with continual feeding of lime and limestone

Cited by 10 publications

References 8 publications

Reactions between calcium oxide and flue gas containing sulfur dioxide at lower temperatures

Reactions between calcium oxide and flue gas containing sulfur dioxide at lower temperatures

Design and Characterization of an Improved Screw-Assisted Rotary Feeding System for Aerosolization of Ultra-Small Quantities of Particulate Solids

A comparison of two-phase and well-mixed models for fluidized-bed polyethylene reactors

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